The present invention relates to a sample container used in the field of biochemistry, physicochemistry, genetic engineering, or the like. Particularly, it is preferably used as a reaction container for PCR (Polymerase Chain Reaction) method. The present invention further relates to a method for producing the sample container.
In the fields of biochemistry, physicochemistry, genetic engineering, and the like, the PCR method is widely used as a method to obtain a great amount of genes each having a specific nucleotide sequence. In the PCR method, a gene is amplified by making use of the property of being single-strand at a high temperature and double-strand at a low temperature and heat resistant polymerase. By the PCR method, a gene can be exponentially amplified by dissociation and annealing of a gene which is caused by repeating ascendance and descendance of temperature of a sample.
In the PCR method, a sample is stored in a reaction container, and a temperature of a constant temperature bath is raised and lowered at suitable intervals so as to raise and lower a temperature of the sample. As such a sample container, a polypropylene tube has been used because of its excellent chemical resistance and moldability.
Usually, 20-30 cycles of temperature ascendance and descendance are required in order to obtain a desired amount of genes. Accordingly, an efficiency of experimentation depends on a time spent for a temperature ascendance or descendance of a sample to a predetermined temperature. In the fields of biochemistry, physicochemistry, genetic engineering, and the like, not only PCR but also many reactions as well as a general enzyme reaction require a temperature control. Accordingly, a rapid change of a temperature of the sample to a predetermined temperature improves an efficiency of experimentation.
Therefore, from such a view point, there has been desired a development of a sample container which can rapidly conduct heat of a constant temperature bath to a sample. For example, Japanese Patent Laid-Open 4-330272 discloses a sample container in which the outer surface of a Teflon (Trademark, produced by du Pont) tube is coated with a metallic thin film.
However, since the metallic thin film is formed by vapor deposition, sputtering, or the like, and has a thickness of 1 .mu.m or less, a Teflon layer is required to be several hundreds of times or more thicker than a metallic thin film, i.e., 0.3-0.4 mm in order to impart mechanical strength by which the sample container stands the use. Since Teflon has a low heat conductivity, it is impossible to sufficiently enhance heat conductivity of the sample container.
The present invention aims to provide a sample container which has a high heat conductivity and which can rapidly conduct heat of a constant temperature bath to a sample.